Thursday, Jun 16 2011
• 10 a.m. (ET)

Suncreen Labels and Skin Cancer

If you’ve shopped for sunscreens lately, you’re aware of the dizzying number of product choices, but it’s hard to know what kind of protection a particular product actually offers. The FDA has felt your pain, but not especially quickly. After thirty three years of review the agency has come out with new rules about how sunscreen manufacturers can and cannot describe their products.‘Sun block’ is out as is ‘waterproof’, and only products with an SPF value of 15 or above with both U-V-A and U-V-B protection can claim to reduce the risk of cancer and premature aging. Join us to discuss new rules for sunscreen labels and the ongoing battle against skin cancer.

Guests

Dr. Lynn Schuchter
professor and division chief, Hematology-Oncology,
Hospital of the University of Pennsylvania
and leader, Melanoma Program, Abramson Cancer Center of the University of Pennsylvania

Dave Andrews
senior scientist, Environmental Working Group

Dr. Margaret O'Neill
dermatologist

Dr. Stephen Katz
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health

Dr. Janet Woodcock
director, Center for Drug Evaluation and Research at the FDA

Transcript

10:06:54

MS. DIANE REHMThanks for joining us. I'm Diane Rehm. Skin cancers are on the rise. Most of them are curable, especially if caught early. Sunscreens can play an important role, but claims about different products are confusing. The FDA has come up with some new rules about these claims.

10:07:20

MS. DIANE REHMJoining me to talk about the new sunscreen label rules and ongoing efforts to fight skin cancer: Dr. Janet Woodcock, she is director of the Center for Drug Evaluation and Research at the FDA, Dr. Margaret O'Neill, she is a dermatologist here in Washington, and Dr. Stephen Katz of the National Institute of Arthritis, Musculoskeletal and Skin Diseases at the National Institutes of Health.

10:07:59

MS. DIANE REHMOf course, your comments, questions are always welcome. Join us on 800-433-8850. Send us your email to drshow@wamu.org. Feel free to join us on Facebook or Twitter. Good morning to all of you.

10:08:24

DR. JANET WOODCOCKGood morning.

10:08:24

DR. STEPHEN KATZGood morning.

10:08:24

DR. MARGARET O'NEILLGood morning, Diane.

10:08:25

REHMDr. Woodcock, tell us about the new rules for sunscreen labels.

10:08:31

WOODCOCKWell, two days ago, FDA established new standards for sunscreens. And these are testing standards, the tests that sunscreens have to meet to have claims, and also new claims that people start seeing no later than next summer on the sunscreens themselves.

10:08:49

REHMSo tell us about the broad spectrum question. I'm not sure people, even I, understand that.

10:09:00

WOODCOCKWell, what people start seeing is a claim that'll be on the front of the sunscreen that will say broad spectrum if the sunscreen meets certain standards that the FDA has established. And that's a very technical task. But to boil it down, it means that broad spectrum -- it gets the UVA rays that are associated with skin cancer and skin aging, as well as some sunburn, as well as the UVB rays that are associated mostly with sunburn. So it protects against all of those harms from the sun.

10:09:38

REHMAnd what about the SPF above 50? Why are they banned?

10:09:45

WOODCOCKWhat people will -- say, we are proposing, at least, that no sunscreen could have an SPF value greater than 50-plus. The test higher than 50 in the lab, it could only be 50-plus on the label. And the reason is we don't think -- we have no proof, no data that's been submitted to us that shows that more than 50 helps anyone, any more than 50.

10:10:11

REHMSo anything between 15 and 50 would do the job, but anything above 50 is kind of questionable?

10:10:22

WOODCOCKWell, don't forget, there's more of the different chemicals in above 50. They're more expensive, but they also have more exposure to whatever is the sunblock. But we don't know that there's any additional screening value for the consumer on a higher SPF number.

10:10:42

REHMAnd could the chemicals in that above 50 actually be harmful?

10:10:49

WOODCOCKWell, some people have allergies to these. Some people have other irritation. And so our general rule with drugs is only use as much as is needed to do the job.

10:10:59

REHMDr. Janet Woodcock, director of the Center for Drug Evaluation and Research at the FDA. Turning to you, Dr. Katz, what about the incidence of skin cancer today? Is it going up? Is it remaining the same? How serious is the problem?

10:11:20

KATZSkin cancer has become a bigger and bigger problem over the years. It's not only increased in incidence and prevalence -- there are three most common skin cancers, the basal cell cancer, which is the most common, which is locally invasive. If you leave it alone, it just keeps invading tissue and gets bigger and bigger. There is the squamous cell carcinoma that comes from a different cell within the epidermis. That squamous cell carcinoma can spread to other parts of the body, so it's potentially lethal.

10:11:54

KATZAnd, of course, this -- the most potentially lethal of them all, which is melanoma that derives from a melanocyte, a pigment cell within the skin -- that the incidence last year was probably 68,000 Americans with about over 8,000 Americans dying from melanoma. So three types.

10:12:14

REHMSo to what extent do any of these sunblocks help to protect against basal, squamous or melanoma type cancers?

10:12:28

KATZThe -- there is irrefutable evidence that sunscreens will block -- will decrease the incidence of basal cell cancer, of squamous cell cancer and also of a pre-cancer, which I didn't mention, which is the most common, which is an actinic keratosis. The blocking of melanoma is not as clear, but, clearly, we know that melanoma is associated with excess sun exposure.

10:12:58

REHMWhat about questions of premature aging? And, again, thinking about the FDA's rulings on these sunscreens, to what extent do you see premature aging protected as -- or our skin being protected from premature aging as a result of these creams and lotions?

10:13:27

KATZI think the FDA wouldn't allow that claim if it weren't true. These sunscreens, as labeled, would be protecting against UVA. UVA is what causes some of the wrinkling. And, also, there's another aging process that's -- this pigmentation that's caused by the sun's rays and also that may be blocked with this broad spectrum, and I underscore broad spectrum sunscreens.

10:13:57

REHMDr. Stephen Katz of the National Institute of Health. And to you, Dr. O'Neill, to what extent do you think these new rules about labels are going to really help people as they go to choose sunscreens?

10:14:17

O'NEILLWell, I think that a lot of the American public has not been all that aware of the difference between UVA and UVB block. And they look at the SPF number on the bottle...

10:14:29

REHMRight.

10:14:29

O'NEILL...and that's all they think about.

10:14:30

REHMRight.

10:14:31

O'NEILLUVA blocking is actually kind of complicated. The zinc and titanium products have a pretty broad spectrum covered throughout the entire UVA spectrum. All the other sunscreen ingredients which are chemicals -- what we call chemical sunscreens -- only block a portion of the UVA spectrum. So if you look at your sunscreen bottle, there are frequently numerous ingredients listed as active ingredients that are blocking different sections of the UVA spectrum.

10:15:04

O'NEILLAnd some sunscreens have a lot of those, and some sunscreens only block a small section. My understanding is that if you block any portion of the UVA spectrum, currently, you're allowed to say on your bottle that you have UVA block in the sunscreen. But it may be very inadequate. So, hopefully, these new regulations are going to kind of tighten that up a little bit, so that it's easier for people to understand whether they're getting a broad spectrum protection out of their sunscreen or not.

10:15:31

O'NEILLI also think that the numbers have gotten a little out of control. I mean, you can buy SPF 100. I don't know how meaningful that is. I mean, really, especially according to Dr. Woodcock, there's not a lot of data on that. And I think it's more important to take a good solid broad spectrum product and use it correctly than it is to buy SPF 100, slap it on, go to the beach for 10 hours and never re-apply.

10:16:00

REHMAnd that's where you come in as a dermatologist, telling your patients what about these sunscreens and their uses.

10:16:13

O'NEILLI think that many, many people go outside with good intentions. They put sunscreen on initially. They usually do not put enough sunscreen on. For the average-sized person, to cover the entire body, it takes approximately one shot glass full of sunscreen, and I don't know many people who apply that much to begin with. The second problem is that all sunscreens really should be re-applied after a couple of hours outdoors.

10:16:42

REHMA couple of hours?

10:16:43

O'NEILLMm hmm. Usually an hour-and-a-half to two hours is about as long they last, particularly if you're swimming and sweating. But some of the ingredients can also degrade in the sun, some of the UVA blocks. So you need to re-apply with fresh product to make sure you actually have active ingredients on your skin. And most people do not re-apply after two hours.

10:17:02

REHMNow, Dr. Woodcock, will that also be on the label, that this must be applied in this amount and this must be re-applied every two hours?

10:17:18

WOODCOCKCertainly, but it's very hard to relay to consumers exactly what they need to do. There's another feature of the new labels which will be that we're not going to allow waterproof or sweat-proof claims because that makes it sound like, okay, I put it on, and I can go swimming all day. And I'll be fine. And as you just heard, that's not true. So we have established a 40-minute test and an 80-minute test for water resistance.

10:17:45

WOODCOCKAnd it will say on the front, water resistant, 40 minutes, and water -- or water resistant, 80 minutes, if the sunscreen has passed that test. I think that will give consumers a good idea about how long it's probably going to last.

10:18:00

REHMAnd, Dr. O'Neill, as you work with patients, how to get them to comply with that is going to be a key.

10:18:10

O'NEILLYeah, and it's tricky. I think people also only think about sun protection when they're going to the beach. I get many, many patients. When I ask them, are you wearing your sunscreen? They say, oh, yes. Every time I go to the beach, I put it on. And then I say to them, well, do you have it on right now? And the answer is, well, no. I mean, I only was out walking my dog this morning.

10:18:31

10:20:03

REHMAnd as we talk about new rules for labeling on sunscreen, we are joined now by David Andrews. He's senior scientist for the Environmental Working Group. That's a private nonprofit advocacy group. Good morning, David.

10:20:24

MR. DAVE ANDREWSGood morning, Diane, and thanks for having me on the show.

10:20:25

REHMSurely. I gather you take some issue with the FDA's new rules. Tell me why.

10:20:33

ANDREWSCorrect. Our biggest concern, really, is the weak UVA standards that FDA has established. Melanoma cancer rates have been rising faster than any other type of cancer in this country, with an incidence rate that has more than doubled since FDA started work on sunscreen regulations. FDA's new rule will allow companies to state that the use of broad-spectrum sunscreens will decrease the risk of skin cancer.

10:21:00

ANDREWSMy fear of melanoma has been a major motivation, really, for my own sunscreen use. But my worry is that this low UVA protection standard, I don't see that all these products will necessarily reduce cancer. And my question, really, for FDA and Dr. Woodcock is, how does FDA justify setting the weakest standard in the world for UVA protection? Don't the Americans -- doesn't the American public deserve at least the same level of sun protection required in other countries?

10:21:35

REHMWhat are you seeing in other countries that you're comparing to?

10:21:41

ANDREWSA higher level of UVA protection relative to the SPF. And the concern here is that it's the balance of protection across the entire UV spectrum that may put you at greater risk for long-term skin damage and skin cancer.

10:21:58

REHMBut isn't there some indication, as Dr. Woodcock has outlined, that anything above SPF 50 has not been, as yet, shown to be protective?

10:22:18

ANDREWSWell, that's -- we also agree and raised concern with continuing to allow companies to advertise and sell products with SPF greater than 50. But our concern about the weak UVA standard applies to all sunscreens that are going to be sellable with the new label that allows them to state broad-spectrum sunscreen.

10:22:39

REHMSo how would you like to see the label read?

10:22:45

ANDREWSI think having the label read like that, we are okay with that. Our concern is that it's such a weak standard that nearly all products on the market already need it. If these standards had been in place 10 years ago, it would have been a forward-looking standard and really would have pushed the development of more beneficial sunscreens for the consumer.

10:23:06

REHMSo, primarily then, what you're arguing is about the lag time and the long 30 years or more it's taken the FDA to come up with these standards. And you're saying that melanoma has doubled in that period.

10:23:27

ANDREWSCorrect. Melanoma has doubled, and yet we don't see that the new standards are very strong with respect to UVA. It seems that the FDA has caved to industry pressure and will now allow nearly all products on the market to be labeled as broad-spectrum sunscreen.

10:23:43

REHMDr. Woodcock, how do you respond?

10:23:47

WOODCOCKWell, I think, first of all, it's important that sunscreens are only a part of protecting against melanoma and other skin cancers. And the new labels will have directions to consumers that they need to consider the sunscreen only as a part of a regimen of sun avoidance and avoiding excessive sun exposure. And it actually tells them to use hats, sunglasses, sun protective clothing, avoid midday sun and so forth. And I think that's a really important message. People can't simply rely on sunscreens.

10:24:21

WOODCOCKAs far as UVA, we proposed something several years ago, and what we found is that the consumers were confused by the star rating for UVA. It was too confusing. Consumers really don't know what UVA is, and they were not able to really process that information effectively. So we have gone to the broad-spectrum standard. The amount of UVA protection will be higher the higher the SPF number, just like the UVB protection will be higher the higher the SPF number.

10:24:54

WOODCOCKSo there is a scale. And the lowest part, which is SPF 15, was set because we do have data that that -- use of that level of broad-spectrum sunscreen will prevent skin cancer.

10:25:09

REHMDr. Katz, what's your response?

10:25:12

KATZMy response is I would underscore what Dr. Woodcock said. Sunscreens are not meant to prevent skin cancer if left -- if you do nothing else. There has to be avoidance of midday sun. There has to be some protection, using hats that protect you all the way around, using sun protective clothing, particularly with children, to be cognizant of the fact that they are being exposed to sun where they have very little protection.

10:25:47

KATZSo even when one uses sunscreen in children, you have to use exposure to ultraviolet light in some moderation because it's all of that that will help protect against these types of devastating public health problems, which are called skin cancer of all type.

10:26:07

REHMAll right. And, David Andrews, I want to come back to you. What about the safety of the sunscreen ingredients themselves?

10:26:19

ANDREWSI think -- we have concerns about a number of the ingredients in sunscreens, including the use of retinyl palmitate vitamin A, which was -- in numerous FDA studies that have taken place over the previous 10 years, has been shown to be photocarcinogenic. And, I'm sorry, but I do have to drop off the call in a minute.

10:26:40

REHMOh, all right. Thanks for being with us. What about that, Dr. Woodcock?

10:26:47

WOODCOCKWe have reviewed all the retinyl palmitate studies. And if we felt any ingredient in sunscreens was actually risky right now to the consumer, we would take steps to remove that from the market and notify consumers. However, we're going to keep looking at the safety of sunscreens. We're not going to stop looking at them. As modern standards have evolved, we have more information. And so you'll be seeing more coming from the FDA about investigations into the safety of sunscreens.

10:27:17

REHMCome back to the question of lag time, Dr. Woodcock. Why did it take more than 30 years to come up with standards that, perhaps, people will now have a bit better understanding of?

10:27:33

WOODCOCKWell, it actually didn't. I mean, that's a facile way to say it -- it took 30 years. But in 1978, when our scientific advisory committee first told us what to do with sunscreens, they recommended we cap the SPF value at 15, that that would be the highest value allowed. So that was the state of the science at the time. By the 1990s, we had established standards for UVB and for the SPF factor, and that's what you've seen.

10:28:01

WOODCOCKAnd we'd also established the allowable ingredients. So those have been available since that time and standardized. What took a while was this determination what to do about the UVA, both the test standard for UVA and what to tell the consumer, how to relay information about broad-spectrum protection to the consumer. But on -- several days ago, we finalized that part of the standard.

10:28:28

REHMSo, Dr. O'Neill, how is this new information likely to change your advice to your patients?

10:28:42

O'NEILLWell, I think it hopefully will encourage my patients to follow what the FDA is saying and use the sunscreen as it should be used: applied regularly, applied before going out in the sun, applied in conjunction with clothing, hats, et cetera. I worry that, even with these regulations, the American consumer may not do what they're supposed to do. And I don't know what else...

10:29:11

REHMWhich is to stay out of the sun, Dr. Katz.

10:29:13

O'NEILLYeah.

10:29:14

KATZRight.

10:29:15

REHMStay out of the sun for the most part. You mentioned children -- particularly vulnerable group.

10:29:25

KATZParticularly vulnerable group. And I think a lot of people are not aware of that so that when one thinks about children, there are sunscreens made for children, non-irritating, that will cover a broad spectrum as well. And it should be remembered that children love to go bathing. And sunscreen, as Dr. O'Neill said, needs to be reapplied because, although some may be water-resistant, they are not forever water-resistant. So...

10:29:58

REHMBut shouldn't the sunscreen for children be even more powerful because their skin is so delicate?

10:30:10

KATZThe SPF 50 would probably cover it. The difference between SPF 50 and SPF 100 is so miniscule that it doesn't make sense to go beyond that. And, basically, the other thing I like about these regulations, actually, is you can't call these things sunblocks anymore -- I think that's right. And the reason is because they don't completely block the sun's rays. They attenuate them. They reduce them. But they don't completely block them. And that's the reason why you have to reapply these sunscreens.

10:30:48

REHMDr. O'Neill.

10:30:49

O'NEILLI just wanted to clarify a couple of points. The American Academy of Pediatrics, several years ago, changed their recommendation. Previously, they had suggested not using sunscreen products on children under the age of six months. They changed that and recommended applying from day one. So I think a lot of people take their babies outside and do not put sunscreen on them when they're very, very young because they think it's contraindicated when, in fact, that's not the case.

10:31:17

O'NEILLAgain, you have clothing as an option, but I think it's important for parents to know that sunscreen should start right away. The other thing, I think, consumers don't realize is that, with regard to this question of SPF 50 and higher, when you apply a sunscreen, if you only apply half of the amount you're supposed to put on, you're really getting about a quarter of the protection because the protection level falls off exponentially with how much you're putting on.

10:31:46

O'NEILLSo this is where some of the higher numbers, I think, sometimes are useful. If you have somebody who is non-compliant with applying it correctly, if they're putting on a higher number, they're still going to end up with some decent SPF level at the end if they're using a higher number. If they start with a 15 and they're getting a quarter of that protection, you know, they're getting a three or a four, which I would consider completely inadequate.

10:32:09

REHMWe have an email from Dennis, who says, "With the increased use of sunscreen products, why is the rate of skin cancer rising, particularly in young people? It doesn't make much sense. If more people are using more and more sunscreen, shouldn't the rate be going down?" Dr. Katz.

10:32:33

KATZSo the increased use of sunscreen may be true. But if one looks at our whole population and one looks at the sunscreen industry, even though it's enormous, and one looks into households as to how much sunscreen a household is using, they may be using one tube per year for an entire household.

10:32:58

KATZSo we have lots of households. There's lots of sunscreens that's sold. But are they being used? Probably not as much as they should be, number one. And, number two, young people don't tend to use them as much as older people.

10:33:13

REHMDr. Stephen Katz of the National Institutes of Health. And you're listening to "The Diane Rehm Show." And here's one more question before we go to the phones. Is there any variation in the effectiveness between spray and lotion, Dr. Woodcock?

10:33:35

WOODCOCKThat's a good question. And, actually, we asked that question in one of the regulatory documents we put out several days ago. We have not finalized anything on the sprays because, number one, we want to know, as consumers use them and spray them on their body versus how you would test them in the laboratory, are they -- do they have the same effectiveness? Obviously, if you sort of wave them over your arm, you're not going to get the level of effectiveness that's put on the label of a sunscreen, a spray sunscreen.

10:34:08

WOODCOCKSo we've asked those questions, and we've also asked questions about safety for inhalation -- potential inhaling that spray accidentally.

10:34:17

REHMAnd another question. A caller who couldn't stay on wants to know what the recommendations are for people of color, Dr. Katz.

10:34:30

KATZWell, the people of color are protected to a much greater extent than people who are very fair-skinned. But people of color do get skin cancer, basal cell and squamous cell cancer, and I think that sunscreens are being used more and more by that population of patients because they are preventing skin cancers, which we are beginning to see in those populations.

10:34:53

REHMAnd we're joined now by Dr. Lynn Schuchter. She is professor and division chief at the hospital of the University of Pennsylvania. Good morning to you.

10:35:07

DR. LYNN SCHUCHTERGood morning.

10:35:08

REHMI hear there are some good news for patients with melanoma. Tell us about the new drugs.

10:35:16

SCHUCHTERYes. And so there's some very exciting new information about the treatment of patients with advanced melanoma. So, as mentioned, melanoma is the serious form of skin cancer. And once it metastasizes beyond the primary site on the skin or lymph nodes, goes to distant sites, such as the lung or the liver or bones. This is a particularly challenging diagnosis. And patients often don't have effective therapy.

10:35:43

SCHUCHTERSo what's very exciting is that a gene has been discovered that's in patients with melanoma. About half the patients have a broken gene called B-Raf. And what's very exciting is there is a new pill, a medicine that targets this broken gene. The medicine is called Vemurafenib.

10:36:06

SCHUCHTERAnd at a recent ASCO meeting, which is a gathering of oncologists, doctors that care for patients with melanoma and advanced cancer, this study show that patients with a broken B-Raf gene had a very high response rate to Vemurafenib, this targeted therapy, compared to chemotherapy, and that the benefit was overwhelmingly better with the targeted agent compared to standard chemotherapy.

10:36:34

REHMBut...

10:36:35

SCHUCHTERAnd this is likely going to lead to FDA approval. So it's a completely new way of approaching the disease and really an exciting time for patients with advanced melanoma with some new approaches to treatment.

10:36:47

REHMI gather, Dr. Schuchter, these new drugs may boost survival rates, but that they don't work for all patients.

10:36:59

SCHUCHTERThat's correct. So this approach with Vemurafenib would only be useful for patients who had a broken B-Raf gene. And that can be tested on a patient's melanoma. Actually, the DNA can be extracted and tested to determine if a patient has a mutated gene. But the other important point is that these new approaches are really exciting and are going to be a great benefit. But these drugs alone are not going to cure melanoma, and it is going to require combinations of therapy to really eradicate advanced melanoma completely.

10:37:35

REHMDr. Lynn Schuchter, she is professor and division chief at the hospital of the University of Pennsylvania. Short break and right back.

10:40:03

REHMWelcome back. And we'll go right to the phones, 800-433-8850. First, to Nashua, N.H. Good morning, Will.

10:40:17

WILLGood morning. I'm -- I like the show. It's a really, really good show. My comment is about the SPF numbers. And I was talking with my dermatologist -- this is a while ago -- and we were talking about the differences between SPF numbers.

10:40:33

WILLAnd she said that anything above 85 is really a waste of money because most of the sunscreens aren't good enough. For, like, 85, they get rid of most of the radiation, already (word?) for radiation. And if you want something more than that, more than 85, you're just wasting your money, just to get that extra 15.

10:40:53

REHMDr. Woodcock.

10:40:55

WOODCOCKYes. What we're proposing is that they be capped right now at 50-plus for the claim of SPF. And we're asking, if there are any special population, say, people with high altitude skiing or some other exposure or disease or condition where they might benefit from those higher SPFs. But we think, for the -- most consumers, SPF 50 is adequate.

10:41:20

REHMDr. Katz, here's an email, "Had there been any longitudinal studies of the long-term effects of using the sun attenuating chemicals on the skin continuously?"

10:41:39

KATZThere have been studies where people have used sunscreens for long periods of time. The FDA has those requirements in terms of its -- of the safety requirements. Dr. Woodcock know them much better that I would know them.

10:41:55

WOODCOCKThere are studies that have been conducted that look at reduction of skin cancer. And some -- in some cases, people are asked to use sunscreen continuously over longer periods of time. The end points of those were mainly reduction in some of these pre-cancerous skin lesions or skin cancer. For safety of sunscreens, we often look at animal testing.

10:42:17

WOODCOCKAnd we do long -- we ask for long-term exposure to the animal skin. And we look at penetration through the skin and so forth. So a lot of safety testing is done on these products.

10:42:29

REHMAnd as far as the FDA is concerned, there are -- thus far, are no long-term effects of using these chemicals?

10:42:41

WOODCOCKThat's correct. If we found any long-term harmful effects, we would notify the public immediately.

10:42:46

REHMOkay. And, by the way, that was not an email. It was a tweet. So let's now go to Joe in Raleigh, N.C. Good morning to you.

10:42:58

JOEHey. Good morning to all. A quick question. The suntan lotions will give -- they have an SPF factor. And based on that, my skin type, I can estimate how long I'd be exposed to the sun. My question is, what's -- how long a period of non-exposure do I have to have? Like, if I go to lunch for an hour or whatever, do I have before -- that time begins again and does it begin again in full?

10:43:27

REHMI'm not sure I understand the question. Do you, Dr. Woodcock?

10:43:31

WOODCOCKI believe he's asking how often should sunscreen be applied...

10:43:34

REHMOn a regular basis, okay.

10:43:37

WOODCOCK...especially if you're not in the sun...

10:43:38

REHMYeah.

10:43:38

WOODCOCK...for part of the time. And don't forget, you do sweat, you know, and so forth that rubs off on clothing. So we recommend re-applying every two hours.

10:43:47

REHMLet's talk about that sunscreen clothing. I know you like it a lot, Dr. O'Neill.

10:43:55

O'NEILLI do. I think it's an excellent idea. They make sunscreen products now, fabrics that have intrinsic SPF 50 -- most of them. They're available broadly. They used to be quite expensive. They've gotten much cheaper. And they make hats with this fabric, as well as shirts, pants, skirts. They make swim -- the swim guard, the swim shirts for children, which are excellent. And they do protect much better than regular fabric.

10:44:27

O'NEILLRegular fabric, especially when it gets wet, loses a lot of its protection, particularly, the lighter colors. So if you're going to wear a regular t-shirt, dark blue is actually your best color...

10:44:38

REHMInteresting.

10:44:39

O'NEILL...followed by dark green, purple and black. But we recommend the protective clothing if you're going to go in the water.

10:44:46

REHMAnd here's an -- another tweet, "What is the shelf life of sunscreen?" The person goes on to say, "I've had a bottle for some time."

10:44:59

O'NEILLYeah, my understanding is that it lasts about two years before it begins to degrade. Once it's degraded, it will not work. You'll burn. My recommendations to my patient always is, if you have a bottle at home, left over, throw it away in the spring time and buy a new one because you have to assume it's been on the shelf for a little while after manufacture. And if you've had it since the previous spring -- you've had it at least a year -- then it's probably close to expiration.

10:45:27

O'NEILLMany people haul that same bottle out year after year out of the closet and put it on.

10:45:30

REHMIf they're using so little, yeah...

10:45:32

O'NEILLThey're not using it. Right. So, number one, the bottle shouldn't be in there that long to begin with. But if it is, throw it away and start again. I don't know if the FDA is going to require expiration dates. I think it would be good because it would encourage people. I think they do check the dates. But if there's not one on there, they're apt to just keep using the same product.

10:45:49

REHMAll right. To Indianapolis. Good morning, Esther.

10:45:54

ESTHERGood morning. I've heard some very good questions this morning. But one in particular that I have not yet heard addressed has to do with the safety of the ingredients, particularly nanoparticles in some of the higher SPF products. And I'm talking not only about safety for human use, especially children, but also safety for aquatic life for folks who swim in lakes and rivers and streams.

10:46:21

REHMGood question.

10:46:24

WOODCOCKWell, FDA has looked into the human safety issue. And we've actually done pretty extensive testing on the titanium dioxide sunscreen nanoparticles. Because the question was, could this get into the body through the skin? These nanoparticles change their behavior when they become very small, and that's why they're clear instead of being these white things you see on people's noses.

10:46:50

WOODCOCKSo our conclusions are that nanoparticles that are in sunscreens do not penetrate into the body. I think the second question about environmental safety is a reasonable question. And that's a separate question.

10:47:04

REHMAnd can you answer that?

10:47:06

WOODCOCKWell, I think the whole administration is looking into the safety of nanoparticles which are now being used in a wide variety of products across all sorts of applications.

10:47:17

REHMDr. Katz, do you want to add to that?

10:47:19

KATZWell, no. I would reinforce the fact that the NIH -- there's a lot of research going on. The Department of Defense got a lot of research going on in nanoparticles not only their usefulness, but also their potential safety risk.

10:47:33

REHMAll right. To Miami, Fla. Good morning, Marie.

10:47:37

MARIEYes, good morning. Actually, I have two questions, but one was already answered. But I have a question -- actually, two now. One is people in Africa don't use sunscreen, and do you have any research as to how much skin cancer they have?

10:47:57

REHMDr. Katz.

10:47:59

MARIEAnd the second one is, does sunscreen affect the absorption of vitamin D that we need?

10:48:08

KATZTwo excellent questions. The first, in Sub-Saharan Africa, there is a skin cancer. That type of skin cancer is mainly melanoma. And the melanoma is seen on the hands and the feet of darkly pigmented people. These are called acral lentiginous melanoma. And just like in Caucasians where there's a mutation in the B-Raf that we heard about, in these types of cancers that are around the hands and feet is -- it's often associated with a c-KIT mutation.

10:48:44

KATZAnd again, we do have a drug that works on these c-KIT mutations. So it's very, very important to know where the tumor comes from, number one, and what the mutation is. And the human genome project has really revealed a lot of that. A lot of that research comes through the human genome project.

10:49:03

KATZThe second question with -- which is an often-asked question is, what about the effect of sunscreens on vitamin D? Vitamin D is made by the skin. And for people who don't get out at all, there are vitamin D supplements. Usually, it takes very little in the way of exposure to ultraviolet light. It doesn't take burning to get enough vitamin D made by your skin.

10:49:34

REHMSo if you're going out for a walk?

10:49:37

KATZSo a 10-minute walk would do it for you. And, unless you are totally covered with sunscreen, you're going to get your vitamin D level.

10:49:49

REHMAll right. I hope that answers it, Mary. And let's see -- John from Cincinnati said he's heard about a new body wash that leaves a protective of 15 SPF. Does it work? Dr. Woodcock.

10:50:11

WOODCOCKBody washes and similar products like that that are newer are not included in what FDA has done. And we have -- we comment on that in our standard setting, that these would not be included and we would not think, unless we would get data, that they could have claimed of sun protection.

10:50:30

REHMHere's another tweet. "Nanoparticles in sunscreen can get into the body through cuts, abrasion, orally, especially in a pool full of children covered in it." What do you say to that, Dr. Woodcock?

10:50:53

WOODCOCKI think that's probably true. And we are performing further research. Of course, the same is true about any sunscreen ingredient, that it would -- if it's used on skin that isn't intact, it could get into the body or if you inhaled it or licked your skin or whatever.

10:51:10

REHMSo you're going to have to be thoughtful and cautious, not only about use of this stuff, but also about letting your child into the pool with a cut or an abrasion or something of the sort, Dr. O'Neill.

10:51:30

O'NEILLYeah, maybe. I don't think there's really any evidence about that one way or the other. And I think that to deny your child the opportunity to swim because they have a skinned knee doesn't make a lot of sense to me. I probably wouldn't slather sunscreen directly over the area. But in terms of what's coming onto the skin from the environment around, you know, in the water, I'm not sure I'm convinced. I think it's -- I don't know.

10:51:59

REHMDr. Woodcock.

10:52:00

WOODCOCKYou know, I think you have to balance the benefits of sunscreen, which are huge, okay, versus these other theoretical risks. And use of any product would have some concern about it. But we know that use of sunscreen along with these other sun-avoidance measures will decrease the rate of cancer and early skin aging and sunburn, which also can be very harmful for children.

10:52:25

REHMDr. Katz.

10:52:26

KATZTwo shorts points: One is if one has denuded skin, one has a scab, if you apply some of these chemicals, they may burn. So as a consequence, you're not going to use them, number one. And, number two, in a pool filled with one or two people using nanoparticles, there is such a tremendous dilution that it's very different than doing a study of thousands or millions of nanoparticles on one's skin. So the dilution factor becomes really important.

10:52:59

REHMDr. Stephen Katz of the National Institutes of Health. And you're listening to "The Diane Rehm Show." Here's a good question from Kristen in Traverse City, Mich. Good morning to you.

10:53:15

KRISTENGood morning. I have a question about the affordability of sunscreens. I'm a stay-at-home mom with two small children. And I have a 2.9-ounce bottle of sunscreen that was over $18. And to be able to put that on my kids, how you're recommending, it would just -- it makes me stay at home.

10:53:32

O'NEILLI think that's where the clothing comes in. You can use the clothing over and over again. It doesn't lose its SPF value unless it's torn, and, over time, it's much more affordable.

10:53:41

REHMYou mean, can you go into and out of the water...

10:53:46

O'NEILLAbsolutely.

10:53:47

REHM...with that clothing? And how long does that SPF value last?

10:53:51

O'NEILLIt's for the lifetime of the piece of clothing. So it's a much better value over time. Yes. You have to make an initial investment. But if you're spending $18 in that tiny bottle of sunscreen, you could probably buy a shirt for your child for that.

10:54:04

REHMWhy is it so expensive? Anybody have any thoughts?

10:54:09

KATZThere are much less expensive sunscreens than $18 per...

10:54:12

REHMAre they just as good, Dr. Katz?

10:54:15

KATZIt depends on the SPF, but I think they are.

10:54:18

REHMAll right. Let's go to Warrenton, Va., and to Barbara. You're on the air.

10:54:26

BARBARAYes. I was going to ask about the vitamin D also, but I have further questions. Does a sunscreen block your use of infrared spectrum of lights? Does it interfere with heat dissipation? And does it block -- I know as you tan, that's one of the uses. Your body makes cholesterol. Cholesterol assisting your skin to help with that process.

10:54:51

WOODCOCKI think anything on your skin would have a small amount of effect on heat dissipation. But, again, I think putting that against the risks that you're trying to mitigate by using sunscreen, that's -- you just have to keep yourself cool, which we would recommend. Of course, by staying out of the sun is the best way to do that. The other question's...

10:55:14

KATZInfrared.

10:55:15

WOODCOCKInfrared. I don't know the answer to that.

10:55:19

REHMNobody does.

10:55:19

WOODCOCKNo.

10:55:20

REHMI'm afraid we'll have to do another show on that, Barbara. Thanks for your call. And from Saint-Tropez, France, Marsha. You're on the air. Very quickly, please.

10:55:32

MARSHAOn the one hand, I wanted -- I want to commend the American Dermatological Society, their professional group, for -- I don't know if they still have it. They used to have, every May, free screenings across America where you make an appointment. I think it's on a Saturday. And you're screened by two dermatologists. And they'll write up a report. And it used to be absolutely free.

10:55:55

REHMOkay.

10:55:55

MARSHAWhere on the other hand, once when I paid for this privately, is that the physician told me not to take off all of my clothes. You have to get naked for this exam. And it's lovely that they -- I don't know if they still do it.

10:56:10

REHMAll right. Dr. Katz.

10:56:11

KATZThis is the American Academy of Dermatology. They sponsor this all over the country. You are right. You have to get naked. You have to look in the intergluteal fold in your buttocks. You have to look within the hair. You have to look between the underarms...

10:56:25

REHMBetween the toes.

10:56:27

KATZ...between the toes. And this is what's done. And many melanomas have been picked up by these screenings that are -- that don't cost anything.

10:56:37

REHMDr. Stephen Katz of the National Institute of Arthritis, Musculoskeletal and Skin Diseases at the National Institutes of Health, Dr. Margaret O'Neill, a dermatologist practicing here in Washington, and Dr. Janet Woodcock, director of the Center for Drug Evaluation and Research at the FDA, thank you all so much.

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